1. Field of the Invention
The present invention relates to an ultrasonic cleaning apparatus, and more particularly to an ultrasonic cleaning apparatus suitable for cleaning a thick web-shaped metal workpiece or a thin filamentary elongate metal workpiece which suffers difficulties producing ultrasonic reflections.
2. Description of the Related Art
One known ultrasonic cleaning apparatus of the type described above has a supply reel with a wound web-shaped or filamentary metal workpiece, a take-up reel for winding the web-shaped or filamentary metal workpiece from the supply reel, and an ultrasonic vibrator for radiating ultrasonic energy toward the workpiece as it is transferred from the supply reel to the take-up reel while being immersed in a cleaning solution stored in a cleaning tank. The workpiece is passed through a position in the cleaning tank where intensive cavitation is developed by the radiated ultrasonic energy, for thereby maximizing the cleaning effect.
The workpiece may be cleaned within a relatively short period of time for increased cleaning efficiency when the workpiece is moved at an increased speed through the cleaning solution. When the workpiece is moved at the increased speed, however, the workpiece passes quickly through the position where intensive cavitation is developed. Therefore, the workpiece may not be sufficiently cleaned because it is not fully exposed to the cleaning effect produced by cavitation.